Massive amount of people are claiming they were logged out of their Facebook app Friday evening. It is unsure what the reason is for this current episode.
Downdetector.com which measures website problems saw the problems start to occur around 10pm EST.
However, in similar previous events it was do to a number of possibilities. Concerns of a data breach, Facebook confirming real users, or a means of updating analytic systems.
This does not means you should be concerned about any of your information being hacked, Facebook has previously been very transparent about such events. However, it is always a good idea to update your password every 60 to 90 days. And avoid using the same password as you use for other online accounts.